DE2156868C3 - Process for the production of phosphoric acid bis (dimethylamide) chloro »or phosphoric acid trls (dlmethylamide) - Google Patents

Description

Phosphoric acid - bis - (dimethylamide) - chloride and Phosphoric acid tris (dimethylamide), hereinafter referred to as amide chloride and triamide, obtained by reacting phosphorus oxychloride with 4 or 6 mol of dimethylamine in an inert solvent (Houben-Weyl, Vol. XII / 2, pp. 445, 446 and 465; 1965). The desired compounds can also be obtained from phosphoric acid dimethylamide dichloride or Phosphoric acid bis (dimethylamide) chloride and each 2 moles of dimethylamine can be prepared (Houben-Weyl, Vol. XII / 2, pp. 446 and 468; 1965, and DT-PS 900 814) After both procedures, the desired phosphorus compound falls together with solid dimethylammonium chloride at. This salt must be removed from the solution of the end product.

On a laboratory scale, the desired amide is obtained from the reaction solution by filtration of dimethylammonium chloride and subsequent distillation of the filtrate obtained.

However, working up the mixture presents considerable difficulties on an industrial scale. Dimethylammonium chloride is obtained in large quantities (e.g. 140 kg of dimethylammonium chloride per 100 kg of triamide _{produced from POCl 3} ) and in a very finely divided form.

With the mechanical !? Separation gives voluminous filter cakes, the large amounts of amide chloride or hold onto Triamid. One must therefore. Wash the salt thoroughly afterwards; one because of the nature of the filter cake very time-consuming process The small grain size also makes it difficult to complete the process Separation of the precipitate. Dimethylammonium chloride which has not been separated off can, however, again make a further clarification of the filtrate in settling tanks necessary because dimethylammonium chloride for example, the decomposition of amide chloride catalyzes in a subsequent distillation (Houben-Weyl, vol. XII / 2, p.446). It also leads the fine-grained dimethylammonium chloride quickly clogs filter cloths or the like Cut-off devices.

It is also known that in the production of amide chloride or triamide from POCI ₃ and di-

methylamine in organic solvents as By-product dimethylammonium chloride is decomposed by aqueous bases and removed from the organic Phase the desired product can be obtained by distillation (US Pat. No. 3,084,190 and US Pat 2 752 392).

These patents show that diraetbylammonium chloride is not desirable in the production of amide chloride and triamide. No solution was found, as without decomposition of the resulting dimethylamine hydrochloride ojne improved Method of obtaining amide chloride and triamide can be achieved. Rather, it was even apart from that; Dimethylamine as chloris to use hydrogen acceptor in the formation of the desired products.

There has now been a process for the production of phosphoric acid bis (dimethylamide) chloride or phosphoric acid tris (dimethylamide) from their solutions in inert organic substances which are immiscible with water Solvents mixed with dimethylammonium chloride found that the disadvantages of previous methods avoids. The method is characterized in that the mixture is treated with water, as then separated off the sieve-separating aqueous phase and optionally the organic phase is distilled.

With these measures, the recovery of amide chloride or triamide from the in the implementation of phosphorus oxychloride compounds with dimethylamine containing dimethylammonium chloride Mixing much easier.

Compared with publications US Pat. No. 3,084,190 and US Pat. No. 2,752,392, amide chloride and triamide are used obtained in improved yields. This is due to side reactions like them run through the use of aqueous alkali in the reaction mixture, and the example to Pyrophosphoric acid (tetrakis) dimethylamide or dem lead corresponding derivative of triphosphoric acid, omitted.

The by-products that do not arise in the process according to the invention must be due to their Toxicity can be removed from the aqueous phase by hydrolyzing it in an acidic medium. Farther In the manufacture of US Pat. No. 3,084,190, twice as much sodium hydroxide was used required as required to be separated from the dimethylamine hydrochloride by the process according to the invention to recover the amine. In addition, there is an additional extraction of the aqueous phase Recovery of the remaining amounts of triamide required, which is not required in the present process. The procedure according to the invention was by no means obvious. It was to be assumed that due to the treatment with water amide chloride and triamide as water-miscible liquids also in the aqueous Phase present and were separated with this and it was also known that phosphoric acid diamides be rapidly decomposed by dilute acidic solutions (Houben-Weyl, vol. XII / 2, p.449), difficulties were bound to arise in the recovery of amide chloride and triamide and considerable losses in yield are expected will.

For obtaining Amidchlorid and the triamide is dimethylammoniumchloridhaltige mixture at temperatures between + 10 and + 50 ⁰ C and 20 to 40 weight percent water on bezoeen Dimi "thvi-

3 O ₄

ammonium chloride, treated The temperatures used, however, are not limited to the specified area Example ί

rffS'fm »rm« Sr ^{hr aUCh Tem} I * ^mtu ™ fish »in a bricked reactor become about

7 ^ USriSiSÄ: aa η · _L 4O ⁰ C warm mixture of triamide, chloroform and

The chamber is expediently watered with stirring. 5 DUnethylammoniumchlorid with stirring

or similar Maiinaamen mixed with water

Ύ? ι! * ·? ^VeTVie f ^ amount of water also greater The mixture was made by converting 445 kg

A SS? FT? · TE ^ f ^{1 Κίη} · Phosphorus oxychloride and the stoichiometric amount of κ ^ ϊ ^ ηί TJn λ ^SI ? M ^Üd ^ ^de ^ ^{Aqueous phase} Dimethylamine prepared in chloroform

removed and, if Amidch ond or Triamid in u> After a stirring time of 5 minutes, the organic

Substance is to be obtained, the inert solution niche phase is separated and chloroform is Ä ÄS, "P ^ J ^ benenfaUs that distilled back. 510 g of phosphoric acid tris- (di-

bleAendeA ^ dchlondoderTrianuddestined. methylamide) as a yellowish colored liquid from

The process of the invention is advanced boiling point 110 ° C / 13 torr

compared to mechanical salt separation. The »5

Example 2 is used to separate off the salt by adding water

very quickly there is a considerable increase in a reaction mixture of phosphoric acid-bis-

the space-time yield. (dimethytamidj chloride, toluene and dimethylammo-

M ° S ^ S ^{an n!} ^ ^e r ^{Dunethylammonium} - niumchlorid, which from 550 kg phosphorus oxychloride,

chlond-separation a similar space-time-Aus ao 2600 kg toluene and 650 kg dimethylamine produced

Achieve prey so if the setup was for it, 2201 water is added and the mixture is stirred for 5 minutes

additional corrosion-resistant container with long and separates the aqueous one after a further 5 minutes

Stirring device, required, from which the separating layer is removed. There remain 3190 kg of toluene solution

device to be loaded. Otherwise it would go back with an amide chloride content of 18.6%.

through the duration of the filtrations or centrifugations a ₅ After 1 day of storage, the content of the

and washes the recovery of amide chloride solution still 18 3 ° /

or triamide considerably delayed. '°

The operation of the invention allows further comparative experiment

filter apparatus or centrifuges and additional components from a reaction mixture of phosphoric acid

equipment or additional container for rewashing 30 bis (dimethylamide) chloride, toluene and dimethyl

and possibly saved ammonium chloride to dissolve the filter cake, which is made up of 550 kg of phosphorus oxychloride.

^we ™ ^en ·. "... _O1 2600 kg of toluene and 650 kg of dimethylamine produced

The dissolution of the salt continues, the dimethylammonium chloride is separated in the pendulum centrifuge with periodic cleaning of the reaction vessel. The centrifuge contents the amide is made of is redundant. It is known that washing is carried out with about 50 liters of toluene in each case, and a layer of dimethylammo often forms there, thrown dry with about 80 liters of hot sodium chloride, which dissolves the cooling of the reaction mixture with water. For this, the water is f a ^e "· intermediate container in a circle ^hwert again and again in the Zen

In addition to the procedural advantages, trifuge offers pumped up to the complete dissolution of the

the operation of the invention continues to have the advantage of 40 filter cake. With a usable volume of the center

DoB a cleaner and, above all, more storage-stable trifle basket from 2001 must include the filling process

Product is still obtained than with mechanical salt removal with subsequent dissolution of the filter cake

separation. repeated three times until after about 8 hours

The process of the invention is advantageously suitable for separating all of the dimethylammonium chloride

for a continuous way of working. You can be at- 45 is. The amount of the toluene filtrate and the washing

for example the pulp from dimethylammonium chloride liquid is 3360 kg with a content of amide

and product solution in an extraction device chloride of 17.5%. This decreases over the course of 2 weeks

treat with water. It can be very high to 16.3% and a colorless one separates out

Achieve throughputs. Solid from

Claims (2)

Patent claims: ί. Process for the production of phosphoric acid bis (dimethylamide > chloride or phosphoric acid tris (dimethylamide) from their solutions in water-immiscible, inert organic solvents mixed with dimethylammonium chloride, characterized in that, that the mixture is treated with water, then the aqueous phase which separates out is separated off and optionally the organic phase is distilled. 2. The method according to claim 1, characterized in that the mixture is ^{treated at temperatures between +10 and +50 0} C with 20 to 40 percent by weight of water, based on dimethylammonium chloride.